初学iptables,请问ICMP、MASQUERADE是什么?
sah 2005-01-15 06:30:06 ALLOWED_ICMP="x x x/x x xx xx xx xx xx"
iptables -N icmpfilter
for TYPE in $ALLOWED_ICMP; do
iptables -A icmpfilter -i $EXT_IF -p icmp \
--icmp-type $TYPE -j ACCEPT
# ------------------------------------------------------------------------------- #
iptables -N block
iptables -A block -m state --state ESTABLISHED,RELATED -j ACCEPT
iptables -A block -m state --state NEW -i ! $EXT_IF -j ACCEPT
iptables -A block -j DROP
# -------------------------------------------------------------------------------- #
iptables -A INPUT -j icmpfilter
iptables -A INPUT -j services
iptables -A INPUT -j block
iptables -A FORWARD -j icmpfilter
iptables -A FORWARD -j block
# --------------------------------------------------------------------------------- #
echo "Masquerading internel network..."
iptables -t nat -A POSTROUTING -o $EXT_IF -j MASQUERADE
请问这几段分别是什么意思?